The unrar command or gui tools are not supported out of the box. Use the following instructions install the same:
unrar Command Line Tool
You need to download unrar by visiting this page and look for OS X version. Alternativly, you can open the terminal and type the following command to download the same:
cd /tmp curl -o output.tar.gz http://www.rarlab.com/rar/rarosx-3.9.3.tar.gz
Untar the tar ball, enter:
tar -zxvf output.tar.gz
Sample outputs:
Fig.01: Unrar Installation - OS X .Rar Extractor
You need to copy rar and unrar command to /bin directory, type the following commands:
sudo cp -v /tmp/rar/{rar,unrar} /bin
rm -rf /tmp/rar
Sample outputs:
Fig.02: Copying files to /bin under OS X
How Do I Use Unrar Command Line?
You can use the unrar command as follows:
Task: Extract Files
The syntax is as follows to open or unrar file in current directory:
unrar e file.rar ls -l
Task: List (l) File Inside Rar Archive
unrar l file.rar
Task: To Extract (x) Files With Full Path
unrar x file.rar
Task: To Test (t) Integrity Of Archive
unrar t file.rar
To see all support command line options type:
unrar | less
GUI App: The Unarchiver
You can use "The Unarchiver" is free software and it is a much more capable replacement for "BOMArchiveHelper.app", the built-in archive unpacker program in Mac OS X. The Unarchiver is designed to handle many more formats than BOMArchiveHelper, and to better fit in with the design of the Finder. Supported file formats include Zip, Tar-GZip, Tar-BZip2, RAR, 7-zip, LhA, StuffIt and many other more and less obscure formats. The goal is to make The Unarchiver able to extract anything you give it.
=> Download The Unarchiver
来源：http://www.cyberciti.biz/faq/unrar-apple-os-x-command-line-gui-tools/